pub struct XdgSurface;
desktop user interface surface base interface
An interface that may be implemented by a wl_surface, for implementations that provide a desktop-style user interface.
It provides a base set of functionality required to construct user interface elements requiring management by the compositor, such as toplevel windows, menus, etc. The types of functionality are split into xdg_surface roles.
Creating an xdg_surface does not set the role for a wl_surface. In order to map an xdg_surface, the client must create a role-specific object using, e.g., get_toplevel, get_popup. The wl_surface for any given xdg_surface can have at most one role, and may not be assigned any role not based on xdg_surface.
A role must be assigned before any other requests are made to the xdg_surface object.
The client must call wl_surface.commit on the corresponding wl_surface for the xdg_surface state to take effect.
Creating an xdg_surface from a wl_surface which has a buffer attached or committed is a client error, and any attempts by a client to attach or manipulate a buffer prior to the first xdg_surface.configure call must also be treated as errors.
After creating a role-specific object and setting it up, the client must perform an initial commit without any buffer attached. The compositor will reply with an xdg_surface.configure event. The client must acknowledge it and is then allowed to attach a buffer to map the surface.
Mapping an xdg_surface-based role surface is defined as making it possible for the surface to be shown by the compositor. Note that a mapped surface is not guaranteed to be visible once it is mapped.
For an xdg_surface to be mapped by the compositor, the following conditions must be met: (1) the client has assigned an xdg_surface-based role to the surface (2) the client has set and committed the xdg_surface state and the role-dependent state to the surface (3) the client has committed a buffer to the surface
A newly-unmapped surface is considered to have met condition (1) out of the 3 required conditions for mapping a surface if its role surface has not been destroyed.